A need exists for accurate, self-calibrating instrumentation capable of monitoring in real time the concentration of blood alcohol as evidenced by the alcohol content of exhaled breath. At present instrumentation capable of diagnosing breath alcohol content requires selection of a specific sample time, is not readily amenable to continuous monitoring and does not take into account interferences or interpersonal differences in metabolism. American Research Corporation of Virginia (ARCOVA) proposes the development of a sensitive self-calibrating sensor array that is capable of differentiating components of human breath and is sufficiently small to be embedded in a headset. The proposal is innovative in developing a redundant electronic nose providing a unique response to exhaled breath concentration and capable of storing a record of breath species for later evaluation. Phase I Specific Aims include evaluation of the sensitivity and selectivity of polymer-dye thin films for use on the SSDL for alcohol sensing, design and fabrication of an experimental workstation for the characterization of an engineering model SSDL array sensor head, acquisition of families of test data from simulated breath exhalant and optimization of the electronic nose continuous monitor and conceptual design of the prototype SSDL array personal breath alcohol monitor. In Phase II of the program, a prototype SSDL-array will be constructed and field-tested in preparation for commercialization during Phase III of the program.